A device that plugs in to your computer's system unit and provides auxiliary functions. (Also called a card.)

The location of an Internet host. An email address might take the form [email protected]; a web address might look like www.xyztech.com.

See Also URL(uniform resource locator).

A computer program designed for a specific task or use, such as word processing, accounting, or missile guidance.

A file, such as a Word document or graphic image, attached to an email message.

The process of turning on your computer system.

A high-speed Internet connection; it's faster than a typical dial-up connection.

A program, such as Internet Explorer, that translates the Hypertext Markup Language of the Web into viewable web pages.

An error in a software program or the hardware.

A device that writes CD-ROMs or DVD-ROMs.

A high-speed, broadband Internet connection via digital cable TV lines.

Also called an add-in board, this is a device that plugs in to your computer's system unit and provides auxiliary functions.

A type of CD drive that lets you record only once onto a disc, which can then be read by any CD-ROM drive or audio CD player.

A CD that can be used to store computer data. A CD-ROM, similar to an audio CD, stores data in a form readable by a laser, resulting in a storage device of great capacity and quick accessibility.

A type of CD that can be recorded, erased, and rewritten to by the user, multiple times.

The group of circuits that directs the entire computer system by (1) interpreting and executing program instruction and (2) coordinating the interaction of input, output, and storage devices.

A programmable device that can store, retrieve, and process data.

Cathode ray tube is a type of video display device that uses a vacuum tube display.

The highlighted area or pointer that tracks with the movement of your mouse or arrow keys onscreen.

Information that is convenient to move or process.

A program for arranging facts in the computer and retrieving them the computer equivalent of a filing system.

The entire screen area on which you display all your computer work. A typical computer desktop can contain icons, a taskbar, menus, and individual application windows.

A computer file that represents some object physical or nonphysical installed on your system.

A high-speed Internet connection that uses the ultra-high frequency portion of ordinary telephone lines, allowing users to send and receive voice and data on the same line at the same time.

A device that stores data in magnetic or optical format.

A mechanism for retrieving information stored on a magnetic disk. The drive rotates the disk at high speed and reads the data with a magnetic head similar to those used in tape recorders.

A portable or removable disk.

The identifying portion of an Internet address. In email addresses, the domain name follows the @ sign; in website addresses, the domain name follows the www.

A way to transfer files, graphics, or other information from the Internet to your computer.

A measurement of printer resolution; the more dots per inch, the higher the resolution.

A support file that tells a program how to interact with a specific hardware device, such as a hard disk controller or video display card.

An optical disc, similar to a CD, that can hold a minimum of 4.7GB, enough for a full-length movie.

Electronic mail; a means of corresponding with other computer users over the Internet through digital messages.

A method of encoding files so only the recipient can read the information.

The most common computer networking protocol; Ethernet is used to network, or hook together, computers so they can share information.

A program you run on your computer system.

A bookmarked site in Internet Explorer.

Any group of data treated as a single entity by the computer, such as a word processor document, a program, or a database.

Computer hardware or software with special security features to safeguard a computer connected to a network or to the Internet.

A high-speed bus used to connect digital devices, such as digital cameras and video cameras, to a computer system. Also known as iLink and IEEE-1394.

A way to group files on a disk; each folder can contain multiple files or other folders (called subfolders).

Free software available over the Internet. This is in contrast with shareware, which is available freely but usually asks the user to send payment for using the software.

One billion bytes.

Pictures, photographs, and clip art.

A sealed cartridge containing a magnetic storage disk(s) that holds much more memory than removable disks up to 400GB or more.

The physical equipment, as opposed to the programs and procedures, used in computing.

The first or main page of a website.

The act of selecting an item by placing your cursor over an icon without clicking.

Hardware used to network computers together, usually over an Ethernet connection.

A connection between two tagged elements in a web page, or separate sites, that makes it possible to click from one to the other.

A graphic symbol on the display screen that represents a file, peripheral, or some other object or function.

Text-based, real-time one-on-one communication over the Internet.

The global network of networks that connects millions of computers and other devices around the world.

A company that provides end-user access to the Internet via its central computers and local access lines.

The typewriter-like device used to type instructions to a personal computer.

A unit of measure for data storage or transmission equivalent to 1,024 bytes; often rounded to 1,000.

A system that enables users to connect PCs to one another or to minicomputers or mainframes.

A portable computer small enough to operate on one's lap. Also known as a notebook computer.

A flat-screen display where images are created by light transmitted through a layer of liquid crystals.

One million bytes.

A measure of microprocessing speed; 1MHz equals 1 million electrical cycles per second.

Temporary electronic storage for data and instructions, via electronic impulses on a chip.

A computer based on a microprocessor chip. Also known as a personal computer.

A complete central processing unit assembled on a single silicon chip.

A device capable of converting a digital signal into an analog signal, which can be transmitted via a telephone line, reconverted, and then “read” by another computer.

The display device on a computer, similar to a television screen.

The largest printed circuit board in a computer, housing the CPU chip and controlling circuitry.

A small handheld input device connected to a computer and featuring one or more button-style switches. When moved around on a flat surface, the mouse causes a symbol on the computer screen to make corresponding movements.

An interconnected group of computers.

A sequence of programming codes that instructs a computer about its various parts and peripherals and how to operate them. Operating systems, such as Windows, deal only with the workings of the hardware and are separate from software programs.

A type of external port used to connect printers and other similar devices.

The collection of folders and subfolders (listed in order of hierarchy) that hold a particular file.

A device connected to the computer that provides communication or auxiliary functions.

The individual picture elements that combine to create a video image.

Hardware that includes its manufacturer and model information in its ROM, enabling Windows to recognize it immediately upon startup and install the necessary drivers if not already set up.

A small browser window, typically without menus or other navigational elements, that opens seemingly of its own accord when you visit or leave another website.

An interface on a computer to which you can connect a device, either internally or externally.

The piece of computer hardware that creates hard copy printouts of documents.

A temporary storage space in which data can be held on a chip rather than being stored on disk or tape. The contents of RAM can be accessed or altered at any time during a session but will be lost when the computer is turned off.

The degree of clarity an image displays, typically expressed by the number of horizontal and vertical pixels or the number of dots per inch (dpi).

A type of chip memory, the contents of which have been permanently recorded in a computer by the manufacturer and cannot be altered by the user.

The main directory or folder on a disk.

A piece of hardware or software that handles the connection between two or more networks.

A device that converts paper documents or photos into a format that can be viewed on a computer and manipulated by the user.

A type of external port used to connect communication devices, such as modems, PalmPilots, and so on.

The central computer in a network, providing a service or data access to client computers on the network.

A software program distributed on the honor system; providers make their programs freely accessible over the Internet, with the understanding that those who use them will send payment to the provider after using them.

See Also freeware.

The programs and procedures, as opposed to the physical equipment, used in computing.

Junk email. As a verb, it means to send thousands of copies of a junk email message.

A program that performs mathematical operations on numbers arranged in large arrays; used mainly for accounting and other record keeping.

Software used to surreptitiously monitor computer use (that is, spy on other users).

The part of your computer system that looks like a big beige or black box. The system unit typically contains the microprocessor, system memory, hard disk drive, floppy disk drives, and various cards.

One trillion bytes.

To add a new or improved peripheral or part to your system hardware. Also to install a newer version of an existing piece of software.

The act of copying a file from a personal computer to a website or Internet server. The opposite of download.

The address that identifies a web page to a browser. Also known as a web address.

An external bus standard that supports data transfer rates of 12Mbps and that can connect up to 127 peripheral devices, such as keyboards, modems, and mice.

A computer program segment or string of code that can attach itself to another program or file, reproduce itself, and spread from one computer to another. Viruses can destroy or change data and in other ways sabotage computer systems.

An HTML file, containing text, graphics, and/or mini-applications, viewed with a web browser.

An organized, linked collection of web pages stored on an Internet server and read using a web browser. The opening page of a site is called a home page.

The radio frequency (RF)-based technology used for home and small business wireless networks, and for most public wireless Internet connections. It operates at either 11Mbps (802.11b) or 54Mbps (802.11g). Short for “wireless fidelity.”

A portion of the screen display used to view simultaneously a different part of the file in use or a part of a different file than the one in use.

The generic name for all versions of Microsoft's graphical operating system.

A vast network of information, particularly business, commercial, and government resources, that uses a hypertext system for quickly transmitting graphics, sound, and video over the Internet.

A file that has been compressed for easier transmission.